1. Field of the Invention
The present invention relates to an image processing device, an image processing method, and a program product. More specifically, the present invention relates to an image processing device suitable for compressing and encoding image data, an image processing method, and a program product.
2. Description of the Related Art
Conventionally, in order to improve compression efficiency during compression and encoding of image data, each attribute region of character, photograph, and graphics is extracted from the image data, and compression and encoding is performed for each attribute region. A technique for identifying an attribute of an image from image data and extracting an attribute region is disclosed, for example, in Japanese Laid-Open Patent Publication No. 05-135202.
On the other hand, a region having a character attribute representing a character is desirably binarized for compression and encoding. A dedicated hardware circuit is often used to increase the processing speed of this binarization. In the dedicated hardware circuit, a memory having a relatively small capacity is used to reduce the device costs, and image data is divided into band data and then binarized. In the hardware circuit for this binarization, when a photograph attribute representing a photograph and a graphics attribute representing graphics are processed according to the band data as a processing unit, the precision for identifying a region is unfortunately degraded. Image data is divided into band data depending on the amount of data, irrespective of the contents of the image data, so that a character, a photograph or graphics may sometimes be divided into a plurality of band data. Therefore, in some cases, for example, while a character is identified as a character in one band data, the character may not be identified as a character in the other band data. If the attribute of a region is mistakenly identified, the compression efficiency decreases.